Here's a roundup of five medical studies published this week that might give you new insights into your health, mind and body. Remember, correlation is not causation – so if a study finds a connection between two things, it doesn't mean that one causes the other.

If watching "The Real Housewives" franchise stresses you out, you may want to assess your real-life relationships.

Researchers in Denmark analyzed the effect of tense social situations on mortality in a large group of middle-aged men and women. They found people who frequently worried about or felt pressured by their partner or children, and those who had frequent conflicts in their relationships had a higher risk of dying in middle age.

Men, the study authors say, seemed to be particularly vulnerable to the effect. And the findings held true even if the study participants' fights were mostly with neighbors, not friends or family. FULL POST

Here's a roundup of five medical studies published this week that might give you new insights into your health, mind and body. Remember, correlation is not causation – so if a study finds a connection between two things, it doesn't mean that one causes the other.

Researchers examined data on 14,828 healthy Korean adults. They found that, compared to people with normal weight, obese participants had a higher prevalence of subclinical coronary atherosclerosis, meaning early plaque buildup in their arteries. This condition, if not managed, can result in heart attack and sudden cardiac death.

"Obese individuals who are considered 'healthy' because they don't currently have heart disease risk factors should not be assumed healthy by their doctors," said lead study author Dr. Yoosoo Chang in a statement. "Our research shows that the presence of obesity is enough to increase a person's risk of future heart disease and that the disease may already be starting to form in their body. It's important that these people learn this while they still have time to change their diet and exercise habits to prevent a future cardiovascular event."

Regenerative medicine saw a breakthrough this week: A study showed how muscle could be regrown in mice and humans.

The human participants were five men who had lost 58% to 90% of one of their leg muscles. To treat them, researchers used a a scaffold made from a pig bladder. This scaffold coaxed stem cells in the men's remaining leg muscle to grow into muscle, too.

"Biological scaffolds, when they degrade, release signal molecules," lead author Dr. Stephen Badylak, of the University of Pittsburgh, told LiveScience. "They can tell cells to do things like divide and line up in a certain way."

Three of the patients showed significant improvement, while the other two had less or no benefit from the procedure.

If you frequent the nail salon, this news is for you: Researchers say there could be a cancer risk associated with the ultraviolet lamps used for nail polish drying. But the risk varies according to the kind of bulb used at the nail salon.

Dr. Lyndsay Shipp and colleagues calculated that at some salons, it may only take 24 visits to accumulate DNA damage caused by ultraviolet radiation that could cause cancer. At other salons, it would take 625 visits.

More research is needed, Shipp told TIME.com. In the meantime, rest assured one manicure won't give you cancer. But if you're concerned, or have a family history, you could wear sunscreen for the ultraviolet light, or just air-dry your nails.

Young patients are at risk of harming themselves if they receive doses of antidepressants that are higher than recommended, a new study says.

There has been mixed evidence on the subject of antidepressant and suicidal behavior among youth in the past. A government review found an association with self-harm, prompting a so-called "black box warning," or warning on the drug's label. But other studies have found no link, and argue that the benefits of these drugs outweigh the risks.

This study, however, specifically examines the connection to dose levels. It looked at three popular drugs: Celexa, Zoloft and Prozac.

Researchers found a risk in self-harm associated with higher-than-recommended doses in patients under age 24. They did not find the same effects in individuals over age 25, or those who took lower drug dosages.

Further study is needed. In the meantime, doctors are recommended to start young patients slowly on antidepressants, at low doses, CBS reports.

Rodents get stressed out in the presence of human males, but less so females, a new study suggests.

The stress hormone corticosterone went up in mice and rats when they were put with a man alone in a room, or were given a T-shirt that a man had worn. Researchers did not observe this high level of stress associated with a woman or female-worn shirt.

This difference could be significant because this hormone decreases the rodents' response to pain, so the results of scientific studies involving rodents could be skewed, depending on who was in the room with the critters.

Apparently, time can reduce the rodent stress effect.

“The ideal solution would be for the male researchers to sit in the room with the rodents for 30 to 60 minutes before conducting experiments,” study author and McGill University psychologist Jeffrey Mogil told the New York Times. “But no one is going to do that.”

Here's a roundup of five medical studies published this week that might give you insights into your health, mind and body. Remember, correlation is not causation, so if a study finds a connection between two things, it doesn't mean that one causes the other.

Researchers believe they've identified four genes that are responsible for your ability to tolerate pain. In their study, they asked 2,721 people with chronic pain to rate their pain on a scale from 1 to 10, 10 being the most painful. Researchers then grouped the participants according to low-pain, moderate-pain or high-pain ratings, and identified which genes were more prevalent in each group.

“Chronic pain can affect every other part of life,” study author Dr. Tobore Onojjighofia said in a statement. “Finding genes that maybe play a role in pain perception could provide a target for developing new therapies and help physicians better understand their patients’ perceptions of pain.”FULL POST

Here's a roundup of five medical studies published this week that might give you new insights into your health, mind and body. Remember, correlation is not causation – so if a study finds a connection between two things, it doesn't mean that one causes the other.

Taking antidepressants during pregnancy may increase your child's risk of autism, especially if the baby is a boy, a new study suggests. Researchers looked at data from 966 mothers and their children. Kids who were exposed to SSRIs, also known as antidepressants, in utero were more likely to have autism or another developmental delay.

The researchers also distinguished between the sexes; boys with an autism spectrum disorder were three times as likely to have been exposed to SSRIs than typically developing children. But the risk of autism remains low, study authors say, and letting depression go untreated could have other serious consequences.

Looks like 40 isn't the start of old age. Neuroscientists say age-related cognitive-motor decline begins at age 24 - and it's all downhill from there. That means that at 24 your reaction time starts to slow, and never picks back up. By 39 your speed has dropped about 15%, researchers found.

Of course, you might be able to compensate for this slower reaction time with skill and experience. If you can still remember what it was like when you were young, that is.

Scientists studying rare diseases should turn to social mediaJournal: Pediatrics

You may have seen the viral video of 4-year-old Eliza O'Neill laughing and playing as her parents talk about her life with Sanfilippo syndrome.

Scientists studying rare diseases often struggle to find patients and funding because so few people are affected. But social media is helping lighten the load. Viral videos and other campaigns often bring people with the same disease together, making it easier for scientists to identify clinical trial patients. In this study, researchers found social media outlets referred 84% of all patients for two pediatric rare disease trials.

The texture of our food affects our perception about its calorie content, says Dipayan Biswas, a marketing professor at the University of South Florida.

In a series of studies, researchers asked people to sample foods that were hard, soft, rough or smooth and then asked them how many calories they thought they had eaten. On average, study participants thought foods that were harder or rougher contained fewer calories.

"Understanding how the texture of food can influence calorie perceptions, food choice, and consumption amount can help nudge consumers towards making healthier choices," the study authors concluded.

Primary care doctors usually have a small window of time to diagnose each patient they see. So it's not a big surprise that mistakes can be made.

A new study finds more than 5%, or about 12 million U.S. adults, are misdiagnosed during an outpatient visit every year. The researchers estimate about half of those errors are harmful to the patient.

“The pressure to move patients in and out and the resulting brief clinical interactions between doctor and patients is a situation that fosters medical errors,” Dr. Otis Brawley of the American Cancer Society told Modern Healthcare.

Being apathetic is usually defined as showing a lack of enthusiasm or energy. Most people who experience it say they just aren’t motivated to do anything.

Although anyone in any age group can become apathetic, it has been well documented that apathy tends to affect those in their golden years. Now scientists believe that an elderly person’s lack of emotion and indifference to the world could be a sign his or her brain is shrinking.

A study published Wednesday in the journal Neurology, and funded by the National Institutes of Health's National Institute of Aging, found that older folks, who are apathetic - but not depressed - may be suffering from smaller brain volumes than those without apathy. FULL POST

If you thought smoking a joint occasionally was OK, a new study released Tuesday suggests you might want to reconsider.

The study, published in the Journal of Neuroscience, is the first to link casual marijuana use to major changes in the brain. And according to the researchers, the degree of abnormalities is based on the number of joints you smoke in a week.

Using different types of neuroimaging, researchers examined the brains of 40 young adults between the ages of 18 and 25 who were enrolled in Boston-area colleges. Twenty of them smoked marijuana at least once a week. The other 20 did not use pot at all. FULL POST

Here's a roundup of five medical studies published this week that might give you new insights into your health, mind and body. Remember, correlation is not causation – so if a study finds a connection between two things, it doesn't mean that one causes the other.

The next time you hear an "achoo!" nearby, shield yourself. A new study shows people blow out gas clouds when they sneeze or cough - and these clouds propel germs further than previously thought.

Scientists at MIT studied how coughs and sneezes move in slow motion using high-speed imaging, in addition to mathematical modeling techniques and simulations. They found that coughs and sneezes have two phases: A quick, jet-like propulsion of droplets, and then a "puff" in which the droplets are suspended in a gas cloud.

When the researchers analyzed the trajectory of the expelled particles, they found that relatively large droplets in the clouds - measuring 100 micrometers in diameter - moved five times further than previous studies had shown. The smaller ones, 10 micrometers across, traveled 200 times farther.

So stop the spread of disease by covering your coughs and sneezes.

Fathers' obesity may be related to children's autism
Journal: Pediatrics

As scientists continue to explore the potential causes of autism, a question has been raised about paternal obesity.

Researchers looked at a large sample of 92,909 children from the Norwegian Mother and Child Cohort Study. The children were between 4 and 13 years old.

Although a mother's weight was only weakly linked with autism in her child, an obese father was associated with a significant increase in risk. Children of obese fathers had a 0.27% likelihood of an autistic disorder, compared to 0.14% for children whose fathers were at a normal weight.

The general risk of an obese father having a child with autism is still small, study authors noted, but the association is worth further study.

"It would definitely be beneficial to replicate our analyses in population studies from other countries," lead researcher Dr. Pal Suren, of the Norwegian Institute of Public Health in Oslo, told HealthDay News.

Mild cognitive impairment is a condition affecting memory and thinking that is a risk factor for Alzheimer's disease and dementia. We don't know how to prevent or cure MCI, but there is some indication that exercise may help.

A new study looked at 86 women between the ages of 70 and 80 who had probable mild cognitive impairment. The women were randomly assigned to aerobic exercise, resistance training, or balance and tone training (the control group) for 26 weeks. Researchers measured the volume of the hippocampus, a brain structure involved in memory, in participants before and after the interventions.

Those who had done aerobic exercise showed bigger hippocampal volume after the intervention, compared to the group that did balance and tone. Those who did resistance training did not show the benefit.

Strangely, those who had larger hippocampal volume also tended to score worse on a verbal learning test. This was a small study and more research is needed to explain the findings.

Scientists have uncovered how cells that lie under the surface of your skin allow you to perceive details and textures. These cells are called Merkel cells.

“These experiments are the first direct proof that Merkel cells can encode touch into neural signals that transmit information to the brain about the objects in the world around us,” researcher Ellen Lumpkin said in a statement.

The work could have implications for understanding conditions in which touch sensitivity is lost. Sensitivity also declines with normal aging; at the same time, Merkel cells start disappearing in people in their early 20s.

“It’s an exciting time in our field because there are still big questions to answer, and the tools of modern neuroscience give us a way to tackle them,” Lumpkin said.

Poor eating habits may not only expand your waistline, but also make you less motivated, a new study suggests.

Researchers fed some rats a low-fat diet that was high in simple sugars and refined flour, and others a healthier diet. All rats learned that they would be able to get a bit of sugar water as a reward for pressing a lever. The number of lever presses required to access to the reward increased during the experiment.

Eventually both sets of rats tired of this exercise, but junk-food rats gave up a lot sooner than the ones who had a healthy diet. Both groups seemed to have similar energy levels, so researchers believe there's something happening in the brains of the ones eating poorly to explain the behavior difference. More research is required to find out if that's true.

Note that this research was in rats, so we don't know how it will apply to humans. Still, lead author Aaron Blaisdell told the LA Times: "Rats are a great animal model for humans because there is so much overlap in the systems that regulate appetite and metabolism."

Here's a roundup of five medical studies published this week that might give you new insights into your health, mind and body. Remember, correlation is not causation – so if a study finds a link between two things, it doesn't mean that one causes the other.

Depending on who you ask (and the diet trend of the week), carbohydrates can be your best friend or worst enemy when it comes to losing weight. New research suggests the truth may lie in our genes.FULL POST

Get a behind-the-scenes look at the latest stories from CNN Chief Medical Correspondent, Dr. Sanjay Gupta, Senior Medical Correspondent Elizabeth Cohen and the CNN Medical Unit producers. They'll share news and views on health and medical trends - info that will help you take better care of yourself and the people you love.